Don't use outlier elimination if you don't use weighting correctly. The graph shows data simulated with Gaussian scatter with a standard deviation equal to 10% of the Y value. The left panel shows our method used incorrectly, without adjusting for the fact that the scatter increases as Y increases. Four outliers are identified, all incorrectly. The right panel shows the correct analysis, where weighted residuals are used to define outliers, and no outliers are found.
Motulsky and Brown BMC Bioinformatics 2006 7:123 doi:10.1186/1471-2105-7-123